Content provided on High-Definition (HD) Digital Video/Versatile Discs (DVD), with either Blu-ray or HD-DVD standards technologies, brings many more features than just a better visual experience. Among these features can include enhanced copy protection, such the Advanced Access Content System (AACS). AACS is a standard for content distribution and digital rights management (DRM), intended to restrict access to and copying of the content found on the next generation of optical discs and DVDs and high-definition media.
Since around 2006 when devices began including the functionality to play back content protected using enhanced copy protection mechanisms, such as AACS, “hackers” ranging from enthusiastic home computer hobbyists to malicious users using advanced techniques on personal computers (PCs), in particular, have been able to retrieve decryption keys used to protect the content. In general, these hackers take advantage of a PC software players' weaknesses to exploit the enhanced copy protection mechanisms. As a result, AACS decryption keys in particular have been extracted from weakly protected PC software players. These decryption keys have further been published around the Internet for use by others. While measures may be taken to revoke the corrupted or exposed decryption keys, it is usually only a matter of time before new keys are exposed or corrupted using the same techniques.
Most copy protection mechanisms propose having a trusted processor. The trusted processor can forbid or otherwise disallow unauthorized applications or even the user from accessing memory in the clear that would expose decrypted data that is otherwise stored as encrypted data. Recently, most if not all consumer electronic devices that include these enhanced copy protection mechanisms, such as those that play AACS protected content, incorporate some form of trusted processor architecture. Yet, trusted processor architectures may not be able to prevent applications or users from accessing data once the data has left a device, such as when the device requests authorization from a remote server to locally access protected content. Additionally, extending existing trusted processor architectures can increase the complexity of a device, and thus can also increase the cost of consumer electronics.
Accordingly, what is desired are improved methods and apparatus for secure remote content activation and/or unlocking that solves at least some of the problems discussed herein of prior solutions. Additionally, what is desired are improved methods and apparatus for reducing at least some of the drawbacks discussed herein of prior solutions.